The present invention relates to a personal computer configured using a 32-bit microprocessor.
Various types of personal computers, each having a combination of an 8-bit MPU (Micro Processing Unit) and a peripheral LSI family, are available as low-end computer products. Middle-end personal computers employing 16-bit MPUs compatible with 8-bit MPU software have recently been developed and are becoming popular. The 8-bit models are gradually being replaced by 16-bit models, through utilizing a wealth of software created on the 8-bit MPU basis.
In addition, 32-bit MPUs have recently been developed to configure top-end personal computers. Demand has thus arisen for personal computers utilizing combinations of 32-bit MPUs and existing peripheral LSI families.
However, the development of 32-bit MPUs has been protracted, compared with that of 16-bit MPUs, for the following reason: It is difficult to design architecture for establishing compatibility between 8-, 16-, and 32-bit MPUs. Therefore, it is difficult to establish compatibility between 32- and 16-bit personal computers.